A year ago, the thought that Robert F. Bennett, a conservative Mormon Republican incumbent from Utah, could lose his Senate seat in the absence of any scandal was nearly unimaginable.

But it happened. And now the same set of treacherous circumstances is starting to fall into place for Mr. Bennett’s fellow Utah Republican, Sen. Orrin G. Hatch, who will be on the ballot in 2012.

Like Mr. Bennett, Mr. Hatch has served Utah for many years — maybe too many. The political mood among Republican voters favors fresh faces with tea party connections, and while the 76-year-old Mr. Hatch may be a veritable political institution in his state, he’s not exactly fresh.

For all his conservative credentials — Mr. Hatch boasts an 89 percent lifetime rating from the American Conservative Union — the six-term senator lacks the hard-right edge of the new Republican wave of lawmakers, such as Sen. Mike Lee, who occupies Mr. Bennett’s former seat.

A war of sorts has broken out among tea party factions over Mr. Hatch, with some groups vowing a primary challenge next year and others defending him.

“Hatch is old school,” said Brad Coker, managing director of Mason-Dixon Polling & Research. “Hatch has always been a guy on the Republican side who would work with Democrats. He was buddies with Ted Kennedy. It’s the bipartisan Republicans who have been getting chewed up in these contested primaries.”

Still, Mr. Hatch’s statewide name recognition, clout in Washington, fundraising prowess and campaign experience ought to count for something — except that they don’t, at least not during Utah’s unusual nominating process.

Utah political parties select their nominees not through a statewide primary vote but through a nominating convention described as the most restrictive in the nation. About 3,500 party delegates choose the nominee through a series of votes, meaning that a candidate who can win over a couple of thousand delegates can win the nomination even with little in the way of popular statewide support.

The nominating delegates tend to be more partisan and less compromising than the average voter, analysts say.

“People attending the convention are more radical, more libertarian and more distrustful of people in Washington, D.C.,” said Kirk Jowers, director of the Hinckley Institute of Politics at the University of Utah, at the time of the Bennett race. “The delegate crowd is a much tougher crowd than the rest of the state.”

An early poll shows Mr. Hatch trailing in hypothetical matchups against other well-known Republican pols in the state. A survey of 504 eligible voters by the Utah Policy/Exoro Group released Jan. 18 showed former Gov. Jon Huntsman leading with 48 percent, followed by second-term Rep. Jason Chaffetz with 23 percent. Mr. Hatch came in third with 21 percent.

Mr. Hatch has reached out to tea party organizations — with mixed results.

One of the main groups of the anti-spending movement, the Tea Party Nation, has targeted Mr. Hatch and four other Republican Senate incumbents for defeat, saying they can be replaced by stronger conservatives.

But Mr. Hatch got a bit of good news late last week when the leader of another influential tea party faction said his group would not be targeting Mr. Hatch.

In an interview with National Review Online, Sal Russo, chief strategist for the Tea Party Express, said his group would lay off Mr. Hatch, citing in part the senator’s decision in the mid-1970s to support the insurgent presidential candidacy of Ronald Reagan against President Ford. Mr. Russo at the time was trying to rally backers for Reagan’s primary run and Mr. Hatch was chairman of Utah’s Republican Party.

Mr. Hatch “has been talking about our issues from the beginning,” Mr. Russo said in the interview. “Orrin is a Reagan conservative as far as I am concerned, and that’s as good as it gets.”

But Mr. Russo’s remarks brought an immediate response from Chris Chocola, the head of the influential anti-spending Club for Growth PAC. The coveted Club for Growth’s endorsements often have helped decide GOP primary battles in recent election cycles.

Mr. Chocola noted that Mr. Hatch had backed the Troubled Asset Relief Program bailout of Wall Street — a program particularly detested in tea party circles — and has a career voting record worse than Mr. Bennett’s on the Club for Growth scorecard.

“We have made no decision about the upcoming Utah Senate race,” Mr. Chocola said, “but when we do, our decision will be about improving the Senate in 2013, not 1977.”

Adding to Mr. Hatch’s woes, a separate Mason-Dixon survey released Nov. 9 found that only 40 percent of likely voters would re-elect Mr. Hatch to a seventh term, while 48 percent said they were inclined to favor someone else. Among Republican voters only, Mr. Hatch’s support rose to 60 percent.

Mr. Huntsman is now serving as the Obama administration’s ambassador to China. Mr. Chaffetz, who has not announced his plans, declined to run against Mr. Bennett last year, but insiders say “he’s now kicking himself,” given Mr. Bennett’s poor showing at the nominating convention.

Mr. Bennett failed to qualify for the statewide primary ballot last year after placing third at the convention. The top two finishers, Mr. Lee and Tim Bridgewater, neither of whom had ever been elected to political office, faced off in the primary race. Mr. Lee, a favorite of many Utah tea party activists, won the primary and then the general election in November.

Mr. Hatch sounds confident of his re-election chances. He has noted that his voting record is slightly more conservative than that of Mr. Bennett, who posted an ACU lifetime record of 86.6. Mr. Bennett was also hurt within Republican ranks by his alternative health care proposal, which he sponsored with Sen. Ron Wyden, Oregon Democrat.

Mr. Hatch is not likely to make the same mistake. He introduced Thursday two bills in the Senate to repeal two basic pillars of President Obama’s health care initiative. His bills would nullify the mandates under Mr. Obama’s plan that all individuals have health care coverage and that larger employers offer health insurance or pay hefty penalties.

The new GOP-dominated House “listened to the American people by voting to repeal Obamacare,” Mr. Hatch said. “Now it’s time for the Senate to follow suit by deploying every available tool to take apart this law.”

Mr. Hatch may not be able to rely on some of his Washington friends during his 2012 campaign. Mr. Bennett received $42,600 from the National Republican Senatorial Committee during his primary race in 2010, but Sen. John Cornyn of Texas, who chairs the NRSC, indicated Tuesday that the group planned to stay out of the 2012 GOP primaries.

Mr. Hatch may find he has better friends in the Utah Legislature, where state House Minority Leader David Litvack has proposed legislation to replace the convention system with direct primary elections.

A direct primary race would allow Mr. Hatch to take full advantage of his name recognition and campaign experience. If the bill fails, however, Mr. Hatch is likely to be in for the fight of his political life.

“If the anti-Washington mood continues through 2012, Hatch is going to have problems,” said Mr. Coker. “He’s going to have to fight the hardest race he’s ever fought.”